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Lock Escalation - What's happening here?
... to take fewer, larger locks (e.g. entire table) instead of locking many smaller things (e.g. row locks).
But this can be problematic when you have a huge table, because taking a lock on the entire table may lock out other queries for a long time. That's the tradeoff: many small-granularity locks...
Why is it not advisable to have the database and web server on the same machine?
...dicated network connection between the two, more maintenance, etc.), especially for a small application, where neither piece is using too much CPU or memory? Even with two servers, with one server compromised, an attacker could still do serious damage, either by deleting the database, or messing wi...
Convert data.frame column format from character to factor
...e to the world of R.
mtcars #look at this built in data set
str(mtcars) #allows you to see the classes of the variables (all numeric)
#one approach it to index with the $ sign and the as.factor function
mtcars$am <- as.factor(mtcars$am)
#another approach
mtcars[, 'cyl'] <- as.factor(mtcars[...
Pairs from single list
...e=2):
it = iter(t)
return izip(*[it]*size)
When you want to pair all elements you obviously might need a fillvalue:
from itertools import izip_longest
def blockwise(t, size=2, fillvalue=None):
it = iter(t)
return izip_longest(*[it]*size, fillvalue=fillvalue)
...
Why do variable names often start with the letter 'm'? [duplicate]
...he Android tutorials such as the Notepad tutorial , I noticed that almost all variables are named starting with the letter 'm'. What convention is this, and where does it originate from?
...
Get the POST request body from HttpServletRequest
... that we cannot read the request body again as getReader has already been called.
– Nikhil Sahu
Jan 6 '17 at 16:08
1
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C# nullable string error
...
For nullable, use ? with all of the C# primitives, except for string.
The following page gives a list of the C# primitives:
http://msdn.microsoft.com/en-us/library/aa711900(v=vs.71).aspx
...
How to remove files from git staging area?
... which I think added too many files to the staging area. How can I delete all the files from the staging area?
14 Answers
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Setting background-image using jQuery CSS property
...rnatively to what the others are correctly suggesting, I find it easier usually to toggle CSS classes, instead of individual CSS settings (especially background image URLs). For example:
// in CSS
.bg1
{
background-image: url(/some/image/url/here.jpg);
}
.bg2
{
background-image: url(/anot...
Working with time DURATION, not time of day
... cell B2 and drag as far down as the A column goes to apply the formula to all data in col A.
Last step, be sure to highlight all of column B and set it to Number format (the application of the formula may have automatically set format to Time).
...